I've had every Fire TV devcie they have made except the 2nd gen Cube I just didn't need another Echo speaker. The Shield is not some godlike device without flaws but the good has always outweighed the bad by leaps and bounds.

Is the ASS subtitles issue a Shield thing or a Plex thing? I don't use them so I don't know. It's OK to just have a Fire TV Stick 4k, or Cube and they have their place but they are built and sold as budget devices and they punch above their price point just like the ONN UHD which outside of Dolby Vision support is every bit the device the Fire TV Stick 4k Max is for half the price. Try using a 2015 Fire TV device with modern content. Long term support where the 2015 version is still viable. The ability to mount network shares device wide. Gigabit Ethernet, of course, the support for lossless audio. I checked with my tech support guy (my son who works in IT) and he said there shouldn't be any problem with 'insecure connection' since i'm only connected to his and his friends' Plex servers.Actual Android TV to start with, more space to start with, and much easier to expand storage even more. I followed the instructions for older TVs, and voila! my tv will now reconnect to the servers I'm allowed. *Note: on some older TV apps the equivalent setting can be found under Settings -> Main -> Allow fallback to insecure connections. To continue to stream securely, we encourage you to consider upgrading your Plex experience with one of several updated and affordable devices, such as Google Chromecast, Roku Express, or Amazon Fire TV Stick. Note that this configuration does allow for the possibility of unencrypted communication (over the internet, when playing remotely) between the TV app and the Media Server, but connections will remain secure for those apps and platforms that support them. If your smart TV app has trouble connecting to a Media Server after September 30th, please ensure that both the app and the server are set to allow insecure connections: On the TV app*, ensure that Settings -> Advanced -> Allow Insecure Connections is set to Always, and on the server, ensure that Settings -> Network -> Secure connections is set to Preferred. I followed the link and found this information in the article:

Plex samsung tv not working 2021